4i6 General Botany 



passing the winter in the granary and in the field. When the 

 grain is harvested and threshed, the smut is spread to the good 



Fig. 257. Early stages in the development of a lichen, showing relation of the hyphae to 

 the algal cells. {After Bonnier.) 



grain. Unless the grain that is used for seed the following year 

 is suitably treated with disinfectants, the smut spores will be 

 planted with the grain the following year. The spores of the 

 commoner smuts germinate readily in water and produce a 

 filament of four cells, each of which then produces a small, 

 thin-walled spring spore (basidiospore) which may infect the 

 young seedling. The smuts of the small cereals usually are carried 

 over from one season to the next in the form of spores on the 

 grain or of hyphae inside the grain. 



Corn smut behaves somewhat differently, in that the entire 

 plant is not usually traversed or invaded by the mycelium. 

 The spores last over from one season to the next in the soil and 



